The 8-bit monolithic digital, analog converter ERS of the DAC08 family provide very high speed performance combined with low cost and outstanding application flexibility. Advanced circuit design achieves a settling time of 85 ns with very low "glitch" energy and at low power consumption. Monotonic multiplication performance is achieved over a wide current range of 20 1 for the reference ENCE. Matched between 1 LSB for reference ENCE and full-scale current, no full trimming is required in most applications. Direct interface to all popular logic families with full noise immunity is provided by high swing, adjustable threshold logic inputs. The high voltage qualified complementary current output specification increases versatility and enables differential operation, effectively doubling the peak-to-peak output swing. In many applications, the output can be directly converted to voltage on-age without the need for an external op amp. All DAC08 series models are fully guaranteed to be 8-bit monotonic, and are not linearly tight ± 0.1% available over the entire operating temperature range. Device performance is essentially constant over a ±4.5 V to ±18 V supply range, and 33 mW of power dissipation is achieved at a ±5 V supply. The compact size and low power consumption make the DAC08 attractive for portable and military/aeronautical applications; handling to MIL-STD- 883 equipment, Class B is available. Applications for the DAC08 include 8-bit, 1 μs A/D converters, servo motors and pen drivers, waveform generators, audio encoders and attenuators, analog pilots, programmable power supplies, CRT display drivers, high-speed modems, etc. Low, fast, full input/output amplifier versatility is required.

Logic inputs are D/A converters in negative or inverting logic. Two outputs can be used simultaneously. If one of the outputs is not needed it must be connected to ground or a point capable of supplying IFS; do not leave unused output pins open. Both outputs have a very wide voltage qualified en abling fast direct current - voltage connected to ground or other voltage source through a resistive converter. Positive compliance is a 36 volt above V-shape, which is independent of the positive power supply. Negative compliance is added by V (I gave REF x 1 kOhm) plus 2.5 V. Dual outputs make the usual peak-to-peak load double pendulum when driving the load in a quasi-differential fashion. This feature is true for cable drives, CRT deflection and is particularly useful for other balanced applications such as driving center-tapped coils and transformers. Power The DAC08 is designed with a unique logic input circuit which allows direct interface to all popular logic families and provides maximum noise immunity. This feature is POS-sible by large input swing capability, 2µA logic input current rent and fully adjustable logic threshold voltage. For V- = -15 V, the logic input can swing between -10 V to +18 V. This allows direct interface to + 15V CMOS logic, even when the DAC08 is powered from a +5 V supply. The minimum in-put logic swing and minimum logic threshold voltage are given by: V-plus (I REF x 1 kΩ), plus the 2.5 V logic threshold can be adjusted over a wide range of logic thresholds by adjusting the appropriate voltage control pins (Pin 1, VLC). Appropriate plots show the relationship between VLC and VTH over this temperature range, with V-shaped TH being nominally 1.4 above VLC. For TTL and DTL interfaces, simply ground pin 1. When interfacing ECL, I REF=1mA is recommended. For other interface logic families, see previous pages. For building logic control circuits in general, it should be noted that pin 1 will output 100µA typical; external circuitry should be designed to accommodate this current. The fastest settling time is obtained when pin 1 sees a low impedance. If pin 1 is connected to a 1kΩ divider, for example, it should be bypassed to ground with a 0.01µF capacitor.

Analog output current

Both true and complementary output sink current is provided where I O+IO = IFS. The current is displayed at the "true" (I O) output when a "1" (high) is applied to each logic input. Due to the increase in binary numbers, the ratio of sink current to pin 4 increases heavily, in the fashion of a "positive logic" D/A converter. When a '0' is applied to any input bit, so that the current can be turned off at pin 4 and turned on to pin 2. The logic count is increased in negative or inverting logic for the D/A converter. Two outputs can be used simultaneously. If one of the outputs is not needed it must be connected to ground or a point capable of supplying IFS; do not leave unused output pins open. Both outputs have a very wide voltage qualified en abling fast direct current - voltage connected to ground or other voltage source through a resistive converter. Positive compliance is a 36 volt above V-shape, which is independent of the positive power supply. Negative compliance is added by V (I gave REF x 1 kOhm) plus 2.5 V. Dual outputs make the usual peak-to-peak load double pendulum when driving the load in a quasi-differential fashion. This feature is true for cable drives, CRT deflection and is particularly useful for other balanced applications such as driving center-tapped coils and transformers.

power supply

The DAC08 operates over a wide range of supply voltages ranging from 9 V to 36 V total supply when operating at layers ±5 V or less, I REF ≤ 1 mA is recommended. Low reference current operation reduces power consumption and increases negative compliance, reference amplifier negative common mode range, negative logic input range, and negative logic threshold range; consult various figures for guidance. For example, running at -4.5 V with IREF = 2 mA is not ommended because the negative output coincides with the weight scaling down to near zero. Operation from lower devices is possible, however at least 8V must always be applied to the internal bias network to ensure conduction. Symmetrical supplies are not needed because the DAC08 is fairly insensitive to changes in supply voltage. Battery operation is possible without the need for a ground connection: however, an artifi-CIAL ground can be used to ensure logic fluctuations etc. remain within an acceptable range for the BE-tween. Power consumption can be calculated as follows: Pd=(I+)(V+)+(I-)(V-). A very useful feature of the DAC08 design is that the supply current is constant and independent of the logic state of the input; this is useful in cryptographic applications and further for reducing the size of the supply bypass capacitors.

temperature performance

The non-linearity and monotonicity specifications of the DAC08 are guaranteed over the entire specified operating temperature range. Full-scale output current drift is low, typically ±10 PPM/°C, with zero-scale output current and the drift is basically negligible compared to 1/2 LSB. The temperature coefficient of reference resistor R14 should be matched and tracked for the total minimum full-scale drift of the output resistance. Settling the DAC08 reduces the approximate time tripartite by 10% at -55°C; at +125°C, an increase of about 15% is typical.